code: def check(self):
      _check_times = 3
      try:
          for _i in range(_check_times):
              assert self.instance_available(self.nvidia_getter())
              if _i < _check_times - 1:
                  sleep(0.5)
      except AssertionError:
          return False
      return True
  
imports: from subprocess import Popen, PIPE
  from threading import Thread, Lock
  from queue import Queue
  from time import sleep
  from sys import stderr
  import re
  import json
label_desc: Use image node_id 4 for calling the GpuChecker obj's underlying member method code with example usage: obj.check() and returns: True, False